scholarly journals Variability of the food potential of the Kerch strait and the black sea pre-strait zone as a prospective area for the development of mollusks Mariculture

2021 ◽  
Vol 258 ◽  
pp. 04007
Author(s):  
Nataliy Sitnik

Based on the data of integrated observations, the variability of phytoplankton, the amount of suspended organic matter and zooplankton of the pelagic zone of the Kerch Strait and the pre-strait zone of the Black Sea is considered. The algal flora of the entire Black Sea, the Kerch Strait and the pre-strait is characterized by the predominance of diatoms over pyridineas (pyrrophytes or dinoflagellates). The study of the species range, number and biomass of the phytoplankton community during several periods of the year showed that its dynamics is largely dependent on seasonal weather changes (climate). In the process of phytoplankton development, several phases of autogenic succession were revealed. It is expressed in a sequential change in phytoplankton forms, changes in its abundance and biomass typical of the eastern shelf of the Black Sea. The zooplankton community of the Kerch Strait is represented by micro-, meso- and macro- zooplankton typical of the Black Sea. Microzooplankton is represented by zooflagellates and protozoa, as well as by early larval stages of planktonic crustaceans, apendicularia and mollusks. Its total biomass averages about 80 mg/m3.The above analysis of the collected material allows us to conclude that the distribution of suspended matter and larvae is related primarily to the peculiarities of water circulation in the strait. In the case of low concentrations of larvae, the dynamic factor can be decisive in the process of sedimentation intensity. The amounts of suspended matter can reach 20 mg/m3, which is 2-3 times higher than on average for the Black Sea. It further demonstrates the high productivity of waters and the prospects of the latter to be the area for commercial growing of mussels.

2021 ◽  
pp. 103513
Author(s):  
Dmitrii A. Kremenchutskii ◽  
Gennady F. Batrakov ◽  
Illarion I. Dovhyi ◽  
Yury A. Sapozhnikov

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 516
Author(s):  
Cihan Cilbircioğlu ◽  
Marta Kovač ◽  
Milan Pernek

Phoretic mites use bark beetles for transportation to new, suitable habitats. Some phoretic mites act as predators and parasitoids of the bark beetles’ immature stages, especially egg and early larval stages, and are potential agents for the biological control of scolytine forest pests. Mites live very frequently in relationships with other invertebrates. Many are found in association with various species of bark beetles. Here, a total of 41 specimens of different bark beetles of the genus Ips (Ips acuminatus, Ips sexdentatus and Ips typographus) were studied for presence, species composition, and abundance of phoretic mites. The beetles were collected on dead wood and parts of tree bark of Pinus nigra, Pinus sylvestris and Picea abies in the Black Sea Mountains in Kastamonu and Artin Province of Turkey. A total of nine mite species were found, including Dendrolaelaps quadrisetus, Ereynetes sp., Histiostoma piceae, Paraleius cf. leontonychus, Pleuronectocelaeno barbara., Proctolaelaps hystricoides, Schizostethus simulatrix, Trichouropoda lamellosa and Uroobovellaipidis. All species are identified for the first time within Turkish fauna.


Author(s):  
Cihan Cilbircioğlu ◽  
Marta Matek Kovač ◽  
Milan Pernek

Phoretic mites use bark beetles for transportation to new, suitable habitats. Some phoretic mites act as predators and parasitoids of the bark beetles’ immature stages, especially egg and early larval stages, and are potential agents for the biological control of scolytine forest pests. One of the most numerous and largest mite orders is Mesostigmata which live very frequently in relationships with other invertebrates. Many are found in association with various species of bark beetles. Here, a total of 41 specimens of different bark beetles of the genus Ips (I. acuminatus, I. sexdentatus and I. typographus) were studied for presence, species composition, and abundance of phoretic mites. The beetles were collected on dead wood and parts of tree bark of Pinus nigra, P. slyvestris and Picea abies in the Black Sea Mountains in Kastamonu and Artin Province of Turkey. A total of 9 mite species in 2 genera were found, including Dendrolaelaps quadrisetus, Ereynetes sp., Histiostoma piceae, Paraleius cf. leontonychus, Pleuronectocaeleno barbara., Proctolaelaps hystricoides, Schizostethus simulatrix, Trichouropoda lamellosa and Urobovella ipidis. All species and genera are identified for the first time within Turkish fauna.


2021 ◽  
Author(s):  
Roman Sedakov ◽  
Barnier Bernard ◽  
Jean-Marc Molines ◽  
Anastasiya Mershavka

<p>The Sea of Azov is a small, shallow, and freshened sea that receives a large freshwater discharge. Under certain external forcing conditions brackish water from the Sea of Azov flow into the north-eastern part of the Black Sea through the narrow Kerch Strait and form a surface-advected buoyant plume. Water flow in the Kerch Strait also regularly occurs in the opposite direction, which results in the spreading of an advected plume of saline and dense water from the Black Sea into the Sea of Azov. Using a regional Black Sea Azov Sea model based on NEMO we study physical mechanisms that govern water exchange through the Kerch Strait and analyze the dependence of its direction and intensity on external forcing conditions. We show that water exchange in the Kerch Strait is governed by a wind-induced barotropic pressure gradient. Water flow through the shallow and narrow Kerch Strait is a one-way process for the majority of the time. Outflow from the Sea of Azov to the Black Sea is induced by moderate and strong northerly winds, while flow into the Sea of Azov from the Black Sea is induced by southerly winds. The direction and intensity of water exchange have wind-governed synoptic and seasonal variability, and they do not depend on the variability of river discharge rate to the Sea of Azov on an intraannual timescale.</p>


Ocean Science ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Ivan Zavialov ◽  
Alexander Osadchiev ◽  
Roman Sedakov ◽  
Bernard Barnier ◽  
Jean-Marc Molines ◽  
...  

Abstract. The Sea of Azov is a small, shallow, and freshened sea that receives a large freshwater discharge. Under certain external forcing conditions low-salinity waters from the Sea of Azov flow into the north-eastern part of the Black Sea through the narrow Kerch Strait and form a surface-advected buoyant plume. Water flow in the Kerch Strait also regularly occurs in the opposite direction, which results in the spreading of a bottom-advected plume of saline and dense waters from the Black Sea into the Sea of Azov. In this study we focus on the physical mechanisms that govern water exchange through the Kerch Strait and analyse the dependence of its direction and intensity on external forcing conditions. Analysis of satellite imagery, wind data, and numerical modelling shows that water exchange in the Kerch Strait is governed by a wind-induced barotropic pressure gradient. Water flow through the shallow and narrow Kerch Strait is a one-way process for the majority of the time. Outflow from the Sea of Azov to the Black Sea is induced by moderate and strong north-easterly winds, while flow into the Sea of Azov from the Black Sea occurs during wind relaxation periods. The direction and intensity of water exchange have wind-governed synoptic and seasonal variability, and they do not depend on the rate of river discharge to the Sea of Azov on an intra-annual timescale. The analysed data reveal dependencies between wind forcing conditions and spatial characteristics of the buoyant plume formed by the outflow from the Sea of Azov.


Author(s):  
Boris N. Panov ◽  
Elena O. Spiridonova ◽  
Michail M. Pyatinskiy ◽  
Aleksandr S. Arutyunyan

The paper presents the results of monitoring the process of migration and fishing of the Azov khamsa in April-May and October-November, 2019. The research used daily maps of sea surface temperature (SST) of the Black and Azov seas, built in the hydrometeorological Center of Russia according to NCDC/NOAA (Operational module Yessim - hmc.meteorf.ru/sea/black/sst/sst_black.htm) and daily fishing information of the Center for Monitoring of Fisheries and Communications. It is shown that in the spring, khamsa clusters begin to disperse and move to feeding places after the water temperature reaches 11 °C, and at a water temperature of 14-15 °C, the fish becomes much more mobile and the clusters finally disperse. In autumn, the Azov khamsa began to concentrate in the pre-flood zone of the Sea of Azov at an average SST of 16-17 °C, with a SST of 14-16 °C, the khamsa went out into the Kerch Strait. The active output of the khamsa into the Black Sea began at the SST of the pre-flood zone of 15 °C and almost stopped at the SST of about 13 °C. The average SST in the Kerch Strait dropped to 11 °C these days.


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